The Myth of the Medical Diagnosis

PETER PRONOVOST: The biggest misperception is certainty. When you receive a diagnosis from a doctor, we don’t always know for 100% sure if it is correct. In reality, medicine is an inexact science. In 2012, Johns Hopkins researchers, including myself, found that in intensive-care units alone, diagnostic errors may account for as many deaths as breast cancer in the U.S.

This is part of a growing body of research highlighting the need to focus on diagnostic accuracy. We need to create health-care systems in which learning is incorporated into daily practice, so that physicians can receive feedback on the accuracy of their diagnoses. We can do this by standardizing care around best practices and standardizing data collection regarding clinicians’ diagnoses and the results they get: Health information technology makes this possible.
Clinicians and patients need to have honest conversations about the certainty of diagnoses, the potential for diagnostic tests (and their costs) or the possibility of getting a second opinion.

For example, if you show up in the emergency room with a headache, there is probably a low risk that you have a stroke or a tumor. But there is not zero risk. A CAT scan or MRI would provide greater certainty, but at much more cost. Consumers will have to be mindful of what they are paying for that certainty.

There’s a real tension here for physicians.

If one acknowledges every uncertainty, it would be paralyzing. If a physician fails to acknowledge when stakes are high, he or she could be wrong and not seek to find the right answer. It has to be a partnership with the patient and family.

It’s not just about what doctors learn in books. It’s about tacit wisdom—the patient’s experience living with the disease and working with the patient and family, often to revise plans. Great physicians balance humility and certainty.